Link efficiency schemes for packet transport

ABSTRACT

In a communication network, link efficiency modules aggregate packets into multiplexed packets to provide efficient use of communication links. To handle varying levels of network traffic, the link efficiency modules provide multiple modes of operation to balance bandwidth efficiency against packet latency.

TECHNICAL FIELD OF THE INVENTION

The present invention relates in general to packet transportationnetworks and, more specifically, to link efficiency schemes for packettransport.

BACKGROUND OF THE INVENTION

Within telephony networks, not all communication links have equalbandwidth. This results in potential bottlenecks through some links. Toprevent these connections from affecting information transportation,some elements will aggregate information to more effectively usebandwidth through potential bottlenecks.

SUMMARY OF THE INVENTION

In accordance with the present invention, link efficiency schemes forpacket transport are provided.

According to a particular embodiment, a method for multiplexing packetsacross varying traffic densities initializes operating parameters usinga first set of multiplexing parameters designed for a first level ofpacket traffic, receives packets using a first interface, forms amultiplexed packet with one or more of the received packets each timethe operating parameters are satisfied, and transmits each formedmultiplexed packet using a second interface. The method monitorsoperating characteristics that predict traffic density at the firstinterface, determines that the operating characteristics indicatetraffic density below a threshold, and in response to the determination,reinitializes the operating parameters using a second set ofmultiplexing parameters designed for a second level of packet traffic.

Embodiments of the invention provide various technical advantages. Thesetechniques provide efficient bandwidth utilization to avoid bottleneckswhile dynamically varying operation to handle different traffic levels.Thus, particular embodiments prevent peak operating characteristics fromimpacting off peak communications. For example, particular embodimentsprovide variation of operating parameters based upon traffic conditionsto prevent the operating parameters from causing delays that may impactvoice quality.

Other technical advantages of the present invention will be readilyapparent to one skilled in the art from the following figures,descriptions, and claims. Moreover, while specific advantages have beenenumerated above, various embodiments may include all, some, or none ofthe enumerated advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and itsadvantages, reference is now made to the following description, taken inconjunction with the accompanying drawings, in which:

FIG. 1 illustrates a telephony communication system having linkefficiency modules operating in accordance with various embodiments ofthe present invention;

FIG. 2 is a block diagram illustrating exemplary functional componentsfor a particular embodiment of a link efficiency module;

FIG. 3 is a block diagram illustrating exemplary functional componentsfor another embodiment of a link efficiency module;

FIG. 4 is a flowchart illustrating a method for varying packetprocessing parameters to account for different traffic levels; and

FIG. 5 is a flowchart illustrating a method for dynamically adjustinglink efficiency operation based upon monitored traffic.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a telephony communication system, indicated generallyat 10, that includes link efficiency modules 12, which provide packetmultiplexing using a dynamic multiplexing scheme. In the embodimentillustrated, system 10 also includes base transceiver stations 14,mobile devices 16, a carrier network 18, and a base station controller20. Within system 10, elements interconnect using various links, such ashigh-speed links 22 and low-speed links 24. In general, link efficiencymodules 12 interface between high-speed links 22 and low-speed links 24and provide dynamically varying packet multiplexing across low-speedlinks 24 to enable efficient bandwidth usage while accounting forvariations in packet traffic density.

In the embodiment illustrated, system 10 provides mobile devices 16access to voice and/or data services through elements of a wirelesscommunication network. While illustrated as wireless telephones, mobiledevices 16 may be any appropriate wireless communication devices, suchas portable digital assistants (PDAs), wireless enabled computers,pagers, or other suitable wireless communication devices. To supportwireless communications, system 10 includes elements of a wirelesscommunication network, including base transceiver stations 14 and basestation controller 20. Base transceiver stations 14 support wirelessconnections with mobile devices 16 to provide devices 16 access to voiceand/or data networks. Thus, stations 14 represent hardware andassociated logic, such as towers and processing equipment, forestablishing wireless communication links with mobile devices 16.

Base station controller 20 represents hardware and controlling logicthat handles traffic for one or more base transceiver stations 14. Basestation controller 20 provides connectivity with voice and/or datanetworks. For example, base station controller 20 may link with a mobileswitching center that provides access to telephony networks such as thepublic switched telephone network (PSTN). Base station controller 20 mayfurther link to an internet protocol (IP) network to provide packetbased data services.

Base station controller 20 and base transceiver stations 14 provideinterfaces for supporting high data rate transmissions. However, basetransceiver stations 14 and base station controller 20 typically link toeach other over bandwidth constrained communication links. For example,stations 14 and controller 20 may connect using leased T1 or E1 linesprovided by a third party carrier. Because these lines are oftenexpensive, network designers attempt to minimize the number ofinterconnecting lines, resulting in the potentially bandwidthconstrained connections between stations 14 and controller 20.Therefore, this description refers to high-speed links 22 and low-speedlinks 24. However, these terms are not meant to limit the operationalcharacteristics of these interconnections or to designate relativetransmission speeds. Rather, these terms are merely meant to illustratethe potential bandwidth constraints that link efficiency modules 12attempt to accommodate.

Link efficiency modules 12 provide multiplexing of information to permitmore efficient bandwidth utilization. This enables relativelyunconstrained traffic on high-speed links 22 to be transported withoutserious delays across low-speed links 24. To efficiently communicateinformation across low-speed links 24, link efficiency modules 12aggregate multiple packets into multiplexed packets for point-to-pointdelivery from one link efficiency module 12 to another link efficiencymodule 12.

For example, for packet communications from station 14 to base stationcontroller 20, link efficiency module 12 labeled A (module A) willdeliver multiplexed packets to link efficiency module 12 labeled C(module C). To form a multiplexed packet, module A aggregates one ormore packets into a single multiplexed packet and transmits themultiplexed packet to module C. The multiplexed packet may be, forexample, a point-to-point protocol (PPP) packet that encapsulatesmultiple user datagram protocol (UDP) packets. Thus, the multiplexedpacket may have a PPP header and trailer surrounding one or more UDPpackets received from station 14. To further reduce bandwidth usage onlow-speed links 24, modules 12 may compress portions of packets receivedfrom stations 14. For example, modules 12 can typically compress UDPheaders from 28 bytes to 3 bytes without impacting communications.However, while this example illustrates encapsulation of UDP packetswithin a PPP packet, system 10 contemplates link efficiency modules 12aggregating any appropriate types of packets for point-to-point deliveryusing any suitable protocols.

When aggregating packets, module 12 uses various parameters to determinehow to form a multiplexed packet. According to particular embodiments,these parameters include a buffer size and a timeout value. When module12 receives sufficient packets to fill a buffer, module 12 forms thosepackets into a multiplexed packet and transmits the multiplexed packet.To prevent packets from unduly languishing in the buffer until itbecomes filled, module 12 may form a multiplexed packet whenever thetime from the last multiplexed packet meets or exceeds the timeoutvalue. This enables module 12 to handle time sensitive information, suchas voice communications, without introducing undue delay.

The values used for buffer size and timeout parameters impact theoperation of module 12 differently during different levels of trafficintensity. During periods of heavy network traffic, a small value forthe buffer size parameter may result in inefficient link usage, andmodule 12 may not be able to handle all of the traffic with low-speedlink 24. Thus a sufficient buffer size parameter can be critical duringpeak traffic periods. During off-peak periods, a relatively large buffersize may cause module 12 to rely upon the timeout parameter to determinewhen to transmit packets that have been accumulated for a relativelylarge proportion multiplexed packets. This can result in unnecessarydelay of packets, since “unfilled” multiplexed packets sit in the bufferuntil the timeout. Therefore, parameters that provide effectiveoperation during peak traffic periods may cause undue transmissiondelays during off-peak periods.

To handle different traffic densities, modules 12 provide two or moremodes of operation. According to particular embodiments, modules 12provide two modes of operation, one for peak traffic periods and one foroff-peak traffic periods. During peak times, modules 12 use operatingparameters designed to handle peak traffic conditions. During off-peaktimes, modules 12 use operating parameters designed to reduce packetlatency while potentially sacrificing bandwidth efficiency. However,because of the lighter traffic density, the decreased bandwidthefficiency will likely not affect capacity.

As an example, consider module 12 configured to provide peak andoff-peak operational modes. During peak traffic, module 12 uses a buffersize value of 250 bytes and a timeout value of two milliseconds. Thus,upon receiving packets totaling at least 250 bytes or if twomilliseconds has passed since the last multiplexed packet, module 12communicates a multiplexed packet. During off-peak periods, module 12uses a buffer size value of 100 bytes and a timeout value of twomilliseconds. Thus, instead of waiting for packets totaling at least 250bytes, module 12 only waits for 100 bytes of information. In thisscenario, module 12 maintains a constant value for the timeout parameterregardless of the operational mode. This permits the timeout value toreflect underlying network requirements. For example, an administratormay set the timeout parameter at or near to a maximum delay allocatedfor this particular segment of network communications.

The preceding example provides specific values for operation of module12 during peak and off-peak modes. However, these values are merelyillustrative, and system 10 contemplates modules 12 using any suitablevalues, based upon network operation, parameters, requirements,protocols, and/or other appropriate criteria. Also, while this exampleillustrates module 12 performing packet multiplexing during both peakand off-peak periods, system 10 contemplates modules 12 completelydisabling packet multiplexing at appropriate times. Thus, for example,modules 12 may perform packet multiplexing during peak operation andperform no packet multiplexing during off-peak operation. Moreover,while the example provides for two modes of operation, system 10contemplates modules 12 providing any number of operational modes torespond to varying network traffic densities.

During operation, module 12 varies its mode of operation based ontraffic characteristics. The following description details threeparticular embodiments for determining a current mode of operation formodule 12. According to one embodiment, modules 12 rely upon upstreamnetwork traffic information to determine a current mode of operation.For example, module A relies upon information from the attached station14 to determine a current mode of operation for multiplexing packets fordelivery to module C. Similarly, module C relies upon information fromthe attached controller 20 to determine a mode of operation formultiplexing packets for communication to module A. This demonstratesthe potential one-way decision-making process used by modules 12. Thatis, modules 12 on opposite sides of a point-to-point connection mayoperate in different modes depending upon network traffic in eachdirection.

For example, if station 14 provides traffic information to module A thatindicates peak or near peak usage, module A operates in peak mode.However, the operation of module A need not impact the current mode ofoperation for module C. Thus, if controller 20 indicates relativelylight traffic coming from attached networks, module C may operate inoff-peak mode.

When operating according to this scheme, elements providing packets tomodules 12 should be configured to provide network traffic information.This potentially enables modules 12 to determine a mode of operationusing perspective traffic information. However, system 10 contemplatesmodules 12 multiplexing packets received from any number and type ofnetwork elements. For example, a single module 12 may simultaneouslyservice packets from stations 14, fixed wireless access points and othernetwork elements. If some of these devices do not provide upstreamnetwork traffic information, module 12 may be unable to appropriatelydetermine a mode of operation using this scheme.

According to another embodiment, modules 12 use link usage statisticsfor low-speed links 24 to determine a current mode of operation. In thisembodiment, module 12 monitors information, such as traffic andutilization of low-speed link 24, to determine whether or not to operatein peak mode. This permits module 12 to determine its mode of operationbased upon downstream information that can be directly monitored.

According to other embodiments, module 12 may determine a current modeof operation based upon traffic flow and operating characteristics. Forexample, module 12 may determine a mode of operation by monitoringmultiplexing operation as compared to preset and/or historicaloperational characteristics. Using this scheme, module 12 can determinea current mode of operation based purely upon packet processing, withoutrelying upon upstream or downstream traffic information.

In a particular embodiment, module 12 compares its recent performance inmultiplexing packets to expected operational characteristics todetermine whether or not to switch between modes. For example, throughanalysis, an administrator may determine that module 12 sends 99% ofmultiplexed packets based upon the buffer size parameter during“healthy” operation. This means that, during healthy operation, module12 communicates undersized multiplexed packets because of the timeoutvalue only one percent of the time. If module 12 determines that recentoperation has resulted in timing out significantly more than onepercent, module 12 may reduce its buffer size parameter. Similarly, ifmodule 12 determines that recent operation has timed out significantlyless than one percent, module 12 may increase the buffer size parameter.This technique permits dynamic variation through a range buffer sizesbased upon analysis of internal operation. However, while the precedingdescription provides a specific method for adjusting buffer size andprovides specific values, system 10 contemplates modules 12 using anyappropriate internal monitoring of operations, values and thresholds asappropriate to switch between modes of operation.

The preceding description details particular embodiments for dynamicallyvarying the mode of multiplexing operation based upon information suchas upstream and downstream traffic and internal operations of module 12.Because each scheme can provide particular advantages, system 10contemplates modules 12 using one or more of these techniques, alone orin combination, during operation. Moreover, system 10 contemplatesmodules 12 using other techniques for dynamically varying operationalmodes to adjust packet multiplexing activity in accordance with networktraffic activity. Also, while system 10 illustrates modules 12 operatingto multiplex packets for a specific type of network, the disclosedconcepts may be suitable for multiplexing packets in any system withpoint-to-point traffic that exhibits variable traffic densities.

FIG. 2 is a block diagram illustrating exemplary functional elements fora link interface module 40 that includes a high-speed interface 42, alow-speed interface 44, a management interface 46, a controller 48, anda memory 50. Module 40 further includes a buffer 52 and a demultiplexer54 coupled between high-speed interface 42 and low-speed interface 44.In operation, module 40 provides multiplexing and demultiplexing ofpackets to provide efficient bandwidth utilization of network link.Module 40 receives packets using high-speed interface 42 and aggregatesthese packets into multiplexed packets for transmission using low-speedinterface 44. Module 40 varies its multiplexing activities based uponnetwork traffic densities. Thus, module 40 provides multi-modaloperation to dynamically adjust multiplexing activity to accommodatevarying network traffic.

High-speed interface 42 provides a link to one or more network elementsacross a relatively high bandwidth connection. For example, high-speedinterface 42 may link module 40 to one or more stations 14 or may linkmodule 40 to base station controller 20. Similarly, high-speed interface42 may link module 40 to any appropriate network elements that generatepackets. Low-speed interface 42 provides an interface to one or morebandwidth constrained network connections. Using low-speed interface 44,module 40 may couple to one or more remote modules 40. These interfaces42 and 44, while each depicted with a single link, may include anynumber and type of connections and pathways formed through anyappropriate media. For example, these interfaces may have multiple portsfor coupling to a number of transport lines and may use multiplepathways on any number of these lines.

Management interface 46 provides an interface for module 40 to receivemanagement and operational information. For example, through managementinterface 46, an administrator may establish settings and configurationswithin module 40. Also, through management interface 46, module 40 mayreceive upstream network traffic information from other networkelements. For example, management interface 46 may couple to station 14and permit station 14 to supply traffic information, such as wirelesslink utilization.

Buffer 52 stores packets received using high-speed interface 42. Buffer52 enables module 40 to generate multiplexed packets that aggregatemultiple packets received using high-speed interface 42. Demultiplexer54 separates multiplexed packets received at low-speed interface 44 intoseparated packets for transmission by high-speed interface 42. Thus,demultiplexer 54 reverses the operation of a remote module 40 inmultiplexing packets. Controller 48 controls the management andoperation of module 40. For example, controller 48 may represent amicroprocessor or a programmed logic device that executes logicalexpressions to control the other elements within module 40.

During operation, elements within module 40 may access informationcontained within memory 50. In the embodiment illustrated, memory 50maintains code 56, configuration information 58, and operationalinformation 60. Code 56 represents software or other suitable logic forexecution by other elements within module 40. For example, code 56 mayinclude microcode for execution by controller 48 to perform multimodalpacket multiplexing. Configuration information 58 includes settings andother appropriate data for controlling the operation of module 40. Forexample, configuration information 48 may include buffer sizes andtimeout values for various modes of operation, thresholds fordetermining when to switch between modes of operation, and othersuitable settings. Operational information 60 details network operatingcharacteristics tracked by module 40. For example, operating information60 may include upstream network traffic information supplied by otherelements of system 10. Similarly, operating information 60 may includelink operation statistics detailing the performance of low-speedinterface 44 for communications on a low-speed link. Operatinginformation 60 may also track performance of module 40 in multiplexingpackets received using high-speed interface 42. This performanceinformation may, for example, permit module 40 to adjust its operationalmode without relying upon upstream traffic information or the operationof low-speed interface 44.

During operation, module 40 provides multimodal packet multiplexing,varying operation in accordance with network traffic. Module 40 supportsmultimodal operation using, for example, techniques such as thosedescribed above. Module 40 also provides for demultiplexing ofmultiplexed packets received from remote devices.

While the illustration and preceding description focus on a particularembodiment of module 40 that includes specific elements, system 10contemplates module 40 having any suitable combination and arrangementof elements for providing dynamically adjustable packet multiplexing.Thus, the modules and functionalities described may be combined,separated, or otherwise distributed among any suitable functionalcomponents, and some or all of the functionalities of module 40 may beperformed by logic encoded in media, such as software and/or programmedlogic devices.

FIG. 3 is a block diagram illustrating another potential configurationand elements for implementing a link efficiency module 80. In theembodiment illustrated, module 80 includes a high-speed line interfacecard 82, multiple low-speed line interface cards 84, a routing module86, and a multiplexing module 88. Multiplexing module 88 provides aseparate element for handling the aggregation of packets intomultiplexed packets. This may, in certain embodiments, restrict theaccess of multiplexing module 88 to upstream and/or downstream networktraffic information. Therefore, the particular embodiment illustratedmay lend itself to multimodal operation based upon internal monitoringof operations.

High-speed line interface card 82 couples module 80 to one or morehigh-speed links 22. Similarly, low-speed line interface cards 84 couplemodule 80 to one or more low-speed links 24. During operation,high-speed line interface card 82 receives packets for transmission bylow-speed line interface cards 84. Similarly, low-speed line interfacecards 84 receive packets for transmission by high-speed line interfacecard 82. According to particular embodiments, the link provided byhigh-speed line interface card 82 provides greater bandwidth than thelinks provided by low-speed line interface cards 84. Thus, at certaintimes, module 80 uses multiplexing module 88 to aggregate packets fromhigh-speed line interface card 82 into multiplexed packets fortransmission by low-speed line interface cards 84.

Routing module 86 provides for routing of packets between various lineinterface cards 82, 84. For example, routing module 86 may distributepackets received by high-speed line interface card 82 among low-speedline interface cards 84. For packets received by low-speed lineinterface cards 84, routing module 86 can forward these packets fortransmission by high-speed line interface card 82. For multiplexedpackets received by low-speed line interface cards 84, routing module 86further provides for demultiplexing of these packets into theirconstituent packets. Therefore, routing module 86 can reverse themultiplexing process performed by a remote link efficiency module.

In the embodiment illustrated, multiplexing module 88 is a separateelement from routing module 86. Thus, for example, multiplexing module88 may be an element such as a daughter card that supports multimodalpacket multiplexing. To perform these operations, multiplexing module 88includes any suitable hardware and controlling logic. For example,multiplexing module 88 may include selected components as illustrated inmodule 40.

Because multiplexing module 88 is separate from routing module 86,multiplexing module 88 may not have access to upstream trafficinformation or link utilization statistics of low-speed line interfacecards 84. Therefore, multiplexing module 88 may rely upon internaloperation to adjust its packet multiplexing operations and/or switchbetween modes of operation. Therefore, multiplexing module 88 may usemethods such as those described above that do not rely upon upstream ordownstream traffic information.

However, multiplexing module 88 may couple to other elements of system10 and/or interface with various elements of module 80 to accessupstream and/or downstream traffic information. Thus, multiplexingmodule 88 may use any suitable techniques and information to dynamicallyadjust packet multiplexing operation in accordance with network traffic.

While this illustration and the accompanying description focus on aparticular embodiment of module 80 that includes specific elements,system 10 contemplates module 80 having any suitable combination andarrangement of elements for providing dynamically varying packetmultiplexing operations. Thus, the modules and functionalities describedmay be combined, separated, or otherwise distributed among any suitablefunctional components, and some or all of the functionalities of module80 may be performed by logic encoded in media, such as software and/orprogrammed logic devices. Moreover, one of skill in the art willappreciate that some or all of the elements of module 40 and module 80may be used in combination.

FIG. 4 is a flowchart illustrating a method for performing packetmultiplexing using a dual mode scheme that dynamically adjusts for peakor off-peak operation. The following description will focus on theoperation of module 12. Module 12 determines parameters for peak andoff-peak operations at step 100. For example, module 12 may accessbuffer size and timeout parameters for peak and off-peak operations thatare stored within memory. Module 12 sets current operating parametersusing peak values at step 102. By beginning operation in peak mode,module 12 ensures that the current operational mode will be sufficientto handle any level of network traffic. However, as previouslydiscussed, while peak mode provides maximum bandwidth efficiency, it canresult in increased packet latency during slower traffic periods.

Module 12 processes packets using current operating parameters at step104. As noted, module 12 initially uses peak operating parameters.Module 12 monitors traffic characteristics at step 106. For example,module 12 may receive upstream network traffic information from elementssupplying packets over high-speed link 22. Alternatively, or inaddition, module 12 may monitor downstream traffic characteristicsand/or internal operations. Module 12 analyzes the trafficcharacteristics based upon the current mode of operation. Thus, module12 determines whether it is operating in peak mode at step 108. If so,module 12 determines whether the traffic characteristics indicate lowlink usage at step 110. For example, module 12 may compare upstreamnetwork traffic information against thresholds to determine whethertraffic is sufficiently light to indicate low link usage. If so, module12 sets the current operating parameters to off-peak values at step 112.In this step, module 12 switches the mode of operation into off-peakoperation. Whether or not a switch is made, module 12 continuesprocessing packets using current operating parameters at step 104.

If module 12 is not currently operating in peak mode at step 108, module12 determines whether the traffic characteristics indicate high linkusage at step 114. For example, module 12 may compare received upstreamnetwork traffic information to a threshold to determine whether theexpected traffic indicates high link usage. Similarly, module 12 maycompare link usage statistics against thresholds to make adetermination. If the traffic characteristics indicate high link usage,module 12 sets current operating parameters to peak values at step 116.This switches the mode of operation into peak operating mode. Whether ornot module 12 switches the mode of operation, module 12 continuesprocessing packets using current operating parameters at step 104.

The preceding flowchart illustrates an exemplary method for dual modemultiplexing of packets. However, while specific steps and operationsare described, system 10 contemplates module 12 using any suitabletechniques and elements for performing similar techniques. For example,while described as initially operating in peak mode, other techniquesmay start up in any appropriate mode. Moreover, many of the steps inthis flowchart may take simultaneously and/or in different orders thanas shown. In addition, module 12 may use methods with additional steps,fewer steps, and/or different steps, so long as the methods remainappropriate.

FIG. 5 is a flowchart illustrating a method for dynamically adjustingpacket multiplexing operations based upon internally calculated linkefficiency statistics. Module 12 initializes buffer size and timeoutvalue parameters at step 130. For example, module 12 may initializethese parameters to peak values. Module 12 initializes expectedoperating characteristics at step 132. For example, module 12 may accessconfigured operating characteristics within a memory, with the expectedoperating characteristics indicating pre-determined characteristics ofhealthy packet multiplexing operations.

Module 12 multiplexes received packets using the current parameters atstep 134. Based upon recent multiplexing operations, module 12calculates link efficiency statistics at step 136. For example, aspreviously discussed, module 12 can determine a percentage of recentlyprocessed multiplexed packets that were communicated as a result oftiming out. Module 12 compares these statistics to expected operatingcharacteristics at step 138. For example, module 12 can comparecalculated percentages to various thresholds for expected operatingcharacteristics.

Module 12 determines whether the calculated statistics vary fromexpected operating characteristics at step 140. If so, module 12modifies current operating parameters at step 142. For example, aspreviously discussed, if the calculated statistics indicate that thetimeout value is resulting in a proportionately large number ofmultiplexed packets, module 12 can reduce the buffer size parameter.Alternatively, if module 12 determines that the timeout value is causinga proportionately small number of multiplexed packets, module 12 canincrease the buffer size parameter. Using various step values and arange of buffer size values, module 12 can provide for two or more modesof operation.

The preceding flowchart and accompanying description illustrate only anexemplary method of operation, and system 10 contemplates module 12using any suitable techniques and elements for varying operatingparameters based upon internal monitoring of operations. Thus, many ofthe steps in this flowchart may take place simultaneously and/or indifferent orders than as shown. Moreover, module 12 may use methods withadditional steps, fewer steps, and/or different steps, so long as themethods remain appropriate. In addition, system 10 contemplates module12 using a variety of information and criteria for varying modes ofoperation. Thus, system 10 contemplates module 12 using techniquesembodied within the preceding two flowcharts as well as additionaltechniques together or separately as appropriate to determine currentmodes of multiplexing packets.

Although the present invention has been described in severalembodiments, a myriad of changes and modifications may be suggested toone skilled in the art, and it is intended that the present inventionencompass such changes and modifications as fall within the scope of thepresent appended claims.

1. A method for multiplexing packets across varying traffic densities,the method comprising: initializing operating parameters using a firstset of multiplexing parameters designed for a first level of packettraffic; receiving packets using a first interface; forming amultiplexed packet with one or more of the received packets each timethe operating parameters are satisfied; transmitting each formedmultiplexed packet using a second interface; monitoring operatingcharacteristics that predict traffic density at the first interface;determining that the operating characteristics indicate traffic densitybelow a threshold; and in response to the determination, reinitializingthe operating parameters using a second set of multiplexing parametersdesigned for a second level of packet traffic.
 2. The method of claim 1,wherein the operating parameters comprise a buffer size and a timeoutvalue.
 3. The method of claim 2, wherein forming a multiplexed packetcomprises: initializing a timer; receiving packets using the firstinterface; determining that received packets meet or exceed the buffersize or that the timer meets or exceeds the timeout value; and based onthe determination, generating a multiplexed packet having a header and apayload portion that aggregates the received packets.
 4. The method ofclaim 2, wherein a buffer size value specified by the first set ofmultiplexing parameters is greater than a buffer size value specified bythe second set of multiplexing parameters.
 5. The method of claim 1,wherein monitoring operating characteristics comprises receivingupstream traffic information from one or more devices coupled to thefirst interface, the devices transmitting packets to the first interfacefor transmission by the second interface.
 6. The method of claim 1,wherein monitoring operating characteristics comprises tracking linkutilization statistics for the second interface.
 7. The method of claim1, wherein: monitoring operating characteristics comprises trackingrecent performance in forming multiplexed packets; and determining thatthe operating characteristics indicate traffic density below thethreshold comprises comparing the recent performance to expectedoperating characteristics.
 8. The method of claim 7, wherein theexpected operating characteristics specify a percentage of times that amultiplexed packet will be formed as a result of a timeout.
 9. A linkefficiency module comprising: a first interface operable to receivepackets; a controller operable to initialize operating parameters usinga first set of multiplexing parameters designed for a first level ofpacket traffic, to form a multiplexed packet with one or more of thereceived packets each time the operating parameters are satisfied, tomonitor operating characteristics that predict traffic density at thefirst interface, to determine that the operating characteristicsindicate traffic density below a threshold, and in response to thedetermination, to reinitialize the operating parameters using a secondset of multiplexing parameters designed for a second level of packettraffic; and a second interface operable to transmit each formedmultiplexed packet.
 10. The module of claim 9, wherein the operatingparameters comprise a buffer size and a timeout value.
 11. The module ofclaim 10, wherein the controller is operable to form a multiplexedpacket by: initializing a timer; tracking packets received using thefirst interface; determining that received packets meet or exceed thebuffer size or that the timer meets or exceeds the timeout value; andbased on the determination, generating a multiplexed packet having aheader and a payload portion that aggregates the received packets. 12.The module of claim 10, wherein a buffer size value specified by thefirst set of multiplexing parameters is greater than a buffer size valuespecified by the second set of multiplexing parameters.
 13. The moduleof claim 9, wherein the controller is operable to monitor operatingcharacteristics by receiving upstream traffic information from one ormore devices coupled to the first interface, the devices transmittingpackets to the first interface for transmission by the second interface.14. The module of claim 9, wherein the controller is operable to monitoroperating characteristics by tracking link utilization statistics forthe second interface.
 15. The module of claim 9, wherein the controlleris operable to: monitor operating characteristics by tracking recentperformance in forming multiplexed packets; and determine that theoperating characteristics indicate traffic density below the thresholdby comparing the recent performance to expected operatingcharacteristics.
 16. The module of claim 15, wherein the expectedoperating characteristics specify a percentage of times that amultiplexed packet will be formed as a result of a timeout.
 17. Acomputer readable medium encoded with computer executable instructionfor multiplexing packets across varying traffic densities, wherein theinstructions are operable when executed to: initialize operatingparameters using a first set of multiplexing parameters designed for afirst level of packet traffic; receive packets using a first interface;form a multiplexed packet with one or more of the received packets eachtime the operating parameters are satisfied; transmit each formedmultiplexed packet using a second interface; monitor operatingcharacteristics that predict traffic density at the first interface;determine that the operating characteristics indicate traffic densitybelow a threshold; and in response to the determination, reinitializethe operating parameters using a second set of multiplexing parametersdesigned for a second level of packet traffic.
 18. The computer readablemedium of claim 17, wherein the operating parameters comprise a buffersize and a timeout value.
 19. The computer readable medium of claim 18,operable to form a multiplexed packet by: initializing a timer;receiving packets using the first interface; determining that receivedpackets meet or exceed the buffer size or that the timer meets orexceeds the timeout value; and based on the determination, generating amultiplexed packet having a header and a payload portion that aggregatesthe received packets.
 20. The computer readable medium of claim 18,wherein a buffer size value specified by the first set of multiplexingparameters is greater than a buffer size value specified by the secondset of multiplexing parameters.
 21. The computer readable medium ofclaim 17, operable to monitor operating characteristics by receivingupstream traffic information from one or more devices coupled to thefirst interface, the devices transmitting packets to the first interfacefor transmission by the second interface.
 22. The computer readablemedium of claim 17, operable to monitor operating characteristics bytracking link utilization statistics for the second interface.
 23. Thecomputer readable medium of claim 17, operable to: monitor operatingcharacteristics by tracking recent performance in forming multiplexedpackets; and determine that the operating characteristics indicatetraffic density below the threshold by comparing the recent performanceto expected operating characteristics.
 24. The logic of claim 23,wherein the expected operating characteristics specify a percentage oftimes that a multiplexed packet will be formed as a result of a timeout.25. A link efficiency module comprising: means for initializingoperating parameters using a first set of multiplexing parametersdesigned for a first level of packet traffic; means for receivingpackets using a first interface; means for forming a multiplexed packetwith one or more of the received packets each time the operatingparameters are satisfied; means for transmitting each formed multiplexedpacket using a second interface; means for monitoring operatingcharacteristics that predict traffic density at the first interface;means for determining that the operating characteristics indicatetraffic density below a threshold; and means for, in response to thedetermination, reinitializing the operating parameters using a secondset of multiplexing parameters designed for a second level of packettraffic.
 26. A method for multiplexing packets across varying trafficdensities, the method comprising: initializing operating parametersusing a first set of multiplexing parameters designed for peak packettraffic, wherein the operating parameters comprise a buffer size and atimeout value, and the first set of multiplexing parameters specify avalue for the buffer size and a value for the timeout value; receivingpackets using a first interface; forming a multiplexed packet with oneor more of the received packets each time the operating parameters aresatisfied, wherein the operating parameters are satisfied if receivedpackets meet or exceed the buffer size or a timer meets or exceeds thetimeout value; transmitting each formed multiplexed packet using asecond interface; monitoring operating characteristics that predicttraffic density at the first interface; determining that the operatingcharacteristics indicate traffic density below a threshold; and inresponse to the determination, reinitializing the operating parametersusing a second set of multiplexing parameters designed for off-peakpacket traffic, wherein the second set of multiplexing parametersspecify a second value for the buffer size and a second value for thetimeout value, the second value for the buffer size less than the firstvalue for the buffer size.